added on nodes for rtdb and firestore andmade nodes pass through msg objects with as little changes as possible

rtdb/rtdb-on.js

@@ -0,0 +1,65 @@
+
+
+let oldpath
+let msgin
+
+module.exports = function(RED) {
+
+  function FirebaseAdmin(config) {
+    RED.nodes.createNode(this, config);
+    var node = this;
+
+    const cb = (res)=>{
+      console.log('firebase get result '+res)
+      //console.dir(res)
+      let val = res.val()
+      //console.dir(val)
+      if(msgin){
+        msgin.payload = val
+        node.send(msgin)
+      } else {
+        node.send({payload: val})
+      }
+
+    }
+
+    let setUpListener = (path)=>{
+      console.log('rtdb-on setUpListener for path '+path)
+      if(oldpath){
+        this.admin.database().ref(oldpath).off('value', cb)
+      }
+      if(path){
+        this.admin.database().ref(path).on('value', cb)
+        oldpath = path
+      }  else {
+        console.log('----- rtdb-on got empty path !!')
+        console.dir(config)
+      }
+    }
+
+    if(config.cred){
+      let c = RED.nodes.getNode(config.cred)
+      this.admin = c.admin
+    }
+
+    //console.log('------------------------------- rtdg-get config')
+    //console.dir(config)
+    this.path = config.path
+    if(this.path){
+      setUpListener(this.path)
+    }
+
+
+    //console.log('configuring rtdb-on to listen for messages')
+    node.on('input', function(msg) {
+      let path = this.path
+      if(msg && msg.payload){
+        path = msg.payload.path
+        msgin = msg
+        setUpListener(path)
+      }
+    }.bind(this));
+
+  }
+  RED.nodes.registerType("rtdb-on", FirebaseAdmin);
+}